## Power System MCQs with Explanatory Answers

* (Generation, Transmission and Distribution MCQs with Explanatory Answers )*

1.* Volume of The Conductor is inversely proportional to the ____________.*

- Voltage (V)
- Half of the Voltage (½ V)
- Squire of the Voltage (V
^{2}) - None of the above

### Show Explanatory Answer

### Show Explanatory Answer

*Answer: 3 Squire of the Voltage (V*^{2})**Explanation:**

Power in Three Phase Circuits P = √3 V I Cosθ OR I = P / √3 V Cos θ (1)

Law’s of resistance = R = ρ (l /A) (2)

Power Loss in Three Phase Circuits = P = 3 I

^{2}R (3)

Putting the Values of I and R from Equation (1) and (2) into Equation (3).

P = 3 (P / √3 V Cos θ)

^{2}x [ρ (l /A)]

P = 3 (P

^{2}/3 V

^{2}Cos

^{2}θ) x ρ (l /A)

P = W = P

^{2 }ρ l/ V Cos

^{2}θ A… OR … A = P

^{2 }ρ l/ V

^{2}Cos

^{2}θ W (4)

Volumeof the conductor in Three Phase System= V

_{ol}= 3A x Length (5)

Putting the value of “A” from Equation (4) into Equation (5)

Vol = 3 P

^{2 }ρ l/ W V

^{2 }Cos

^{2}θ x l

Vol = 3 P

^{2 }ρ

*l*

^{2}/ W V

^{2 }Cos

^{2}θ

**Hence Proved**that Volume of the Conductor is inversely proportional to squire of Voltage

**Volume of the Conductor = Vol ∞ 1/V**

^{2}
Dear If we will put the value of equation (4) into (5) there should be Length^2 even there is no change in the result as this A = P2 ρ l/ V2 Cos2 θ W (4)<br />Volume of the conductor in Three Phase System= Vol = 3A x Length <br /><br />Vol = 3 P2 ρ l^2/ W V2 Cos2 θ

keep it up!